confinement consistent with l-mode but we is small fraction - nstx约束一致的模式但我们是小部分：nstx

National Spherical Torus ExperimentFacility / Diagnostic Overview,Supported by,Columbia UComp-XGeneral AtomicsINELJohns Hopkins ULANLLLNLLodestarMITNova PhotonicsNYUORNLPPPLPSISNLUC DavisUC IrvineUCLAUCSDU MarylandU New MexicoU RochesterU WashingtonU WisconsinCulham Sci CtrHiroshima UHISTKyushu Tokai UNiigata UTsukuba UU TokyoJAERIIoffe InstTRINITIKBSIKAISTENEA, FrascatiCEA, CadaracheIPP, JlichIPP, GarchingU Quebec,Masayuki OnoFor the NSTX Team,46th Annual Meeting of Division of Plasma Physics, American Physical SocietyNovember 15 - 19, 2004Savannah, Georgia,Designed to Study High-TemperatureToroidal Plasmas at Low Aspect-Ratio,Achieved ParametersAspect ratio A1.27Elongation 2.6Triangularity 0.8Major radius R00.85mPlasma Current Ip1.5MAToroidal Field BT00.6TSolenoid flux0.7VsAuxiliary heating & current drive:NBI (100kV)7 MWRF (30MHz)6 MWCHI0.4MAPulse Length1.1sStored Energy400 kJbT 40%,tIp flattop 3.5tskin tW flattop 10 tE bT20%, bN5, tE/tE,L1.5 for 10 tE IBS/Ip = 0.5, IBeam/Ip = 0.1,Operational and Physics Advances Have Led to Significant Progress Towards Goal of High-bT, Non-Inductive Operation,fBS = IBS/Ip = 0.5 e1/2 bpolbT = /(BT02/2m0),H-mode plasma,Research Topics to Achieve Long-Pulse, High Performance Plasmas Are Identified,Enhanced shaping improves ballooning stabilityMode, rotation and error field control allows high betaNBI and bootstrap sustain most of currentHHFW heating contributes to bootstrapEBW provides off-axis current & stabilizes tearing modesParticle and wall control maintains proper density, Successfully operated for 21.1 weeks with 2460 plasmasMet the Joule milestone of 18 weeks and programmatic goal of 20 weeks Significantly expanded plasma operational regimes toward the NSTX longer term goals:High k 2.5 plasma controlled by faster plasma control systemSimultaneous high bT - high j-bootstrap regimes expandedEffective plasma pulse duration (tpulse Ip/ITF) doubled Meeting all the FY 04 research milestones:High beta plasma (bT 25%) sustained for longer than 2 tE MSE-CIF now yielding core current profile informationCore and edge fluctuations measured and characterizedEBW emission measurement suggests good coupling efficiencyNew solenoid-free start-up experiments conducted with “transient” CHI and with outer PF coils,NSTX had a very productive FY 04 Run,Gradual joint resistance increase observed in many stressed joints at 4.5 kG Further joint monitoring revealed greater than anticipated flag movementsFor machine safety, TF limited to 3 kG during the last month of operation Out-of-spec flag movement traced to not-fully-penetrated epoxy fillThrough R&D, a reliable full-penetration epoxy-fill technique developed Other improvements implementedAppropriate design reviews are being conducted,TF-Joints issues being resolved,NSTX plasma operations to resume in Feb. 2005,MHDTools to reach near ideal MHD limits,Improved Plasma Control System Opened Operating Window During 2004 Campaign,Reduced latency improved vertical control at high-k, high-bT,Capability for higher k, d allowed higher IP/aBT Significantly more high-bT(bN=6.8 %mT/MA achieved),More routine high k, dLonger current flattop duration tpulse = t(0.85 Ip,max),Time of peak bT,New PF 1A Coils to improve plasma shaping,Achieved2004,Goal of2005, Shorter PF 1A is needed to improve the plasma shaping control (k = 2.5 and d = 0.8) for advanced ST operations. Due to the success of high k operation this year, the new PF 1A coil will be installed this year ahead of schedule. Should be available for FY 05 run starting in Feb. 05.,Active Control Will Enable Study of Wall Mode Interactions with Error Fields & Rotation at High bT,Ex-Vessel Feedback Control Coil System Status, A pair of the Ex-Vessel Feedback Control Coils installed and energized with the preprogrammed power supply in July, 2004. Several experiments were performed:locked mode control, plasma rotation control, error field amplification, Resistive Wall Modes physics.,Full Ex-Vessel Feedback Control Coil System is scheduled to be available for the FY 05 experimental run.,Transport and ConfinementMeasuring Fluctuations to gain understanding of plasma transportPfusion H5-7,Measured magnetic field pitch in a ST for the first timeMSE-CIF j(r) diagnostic,MSE Multistage Lyot Filter, Calibrated in situ and achieved the desired statistical errors of 0.2/0.4 at 4.5/3.0 kG Initial 8 ch data were collected with 4 ch activated at one time. MSE data being incorporated into EFIT and other codes.,time(sec)MSE-CIF measured q(0) and Raxis q(0) 0.8 before 1 after crash Raxis shift inboard 2 cm after crash 5 msec resolution,Nova Photonic Inc,8 ch will be available for the FY 05 run and increased to 12 - 14 ch.,Correlation length measurements,Reflectometry Turbulence Measurements,UCLA Reflectometer Array of microwave reflectometer horns Aligned perpendicular to magnetic flux surfaces,Fast X-ray Camera Reveals Core Electron Dynamics,Images with time resolution down to 2 s,CCD camera,Image intensifierinside magnetic shield,Pinholes andBe foils,PSI,Image of core n=1 tearing mode,High k scattering measurements will be developed in FY 05,Initial system will allow range of k measurements in select locations (2 - 20 cm-1)Access to ETG possible!Major installation this opening.,High k scattering,Luhmann (UC Davis), Munsat (U. Colorado) Mazzucato, Park, Smith (Princeton U.),UCD,Non-Inductive SustainmentHHFW Off-axis Heating and CDEBW CD for profile control*,Multiple Roles of HHFW, Bulk plasma heating to enhance bootstrap currents in advanced ST Operations Plasma start-up and current ramp-up Super-Alfvnic energetic particle physics (UCI)- HHFW modification of NBI fast ion distribution function- TAE mode stablization Edge physics for RF- Anomalous edge ion heating- Phase dependent heating efficiency- Parametric instabilities,&,12 antennas powered by 6 MW sources,ORNL, UCI, MIT, GA, CompX,EBWs Can Generate Critical Off-Axis Current Drive in NSTX at High b,NSTX, b = 40%,0,0,1,r/a,Charles Kessel (PPPL) Tokamak Simulation Code,Comp-X, 100 kA of off-axis CD neededto sustain b 40% in NSTXCannot use ECCD in NSTX since wpe/wce 3-10Modeling indicates that EBWCD can provide needed currentEBWCD may also assist startupand stabilize NTMs4 MW, 28 GHz EBWCD system planned for NSTX,Strong Diffusion Near Trapped-Passing BoundaryEnables Efficient Ohkawa Current Drive,CompX GENRAY/CQL3D,1 MW “Proof-of-Principal” EBW System Tests Viability of Heating & Current Drive in NSTX,1 MW, 750 kW EBW power delivered to plasma- Use EBWCD to locally drive 30-40 kAIf 1 MW system is successful increase RF power to 4 MW with addition of three more gyrotrons, transmission lines & launchers by - Provide 3 MW of EBW power in the plasma & Generate 100 kA,(CPI or Gycom),Power and Particle HandlingNSTX has largest “P/R” in tokamaks/STs comparable to ITER,viewing area 25x25 cmspatial resolution 1-2 cm,Gas Puff Imaging Diagnostic,RF limiter,separatrix,Using Princeton Scientific Instruments PSI-5 camera 250,000 frames/sec 64 x 64 pixels/frame300 frames/shot, 14 bit digitizer, intensified,Typical image,PSI, Nova Photonics,Fast probe provided edge density and temperarure profile,ne rises faster than Te,UCSD,Outer divertor not detached yet,LLNL,Lithium Pellets Injection to Control Particle Recycling,Capability for injecting solid pellets (1 5 mg) & powder (micro-pellets) 10 200 m/s radial injection1 8 pellets per discharge400 pellet capacity Develop optimized scenarios,Lithium “vapor ball” surrounding pellet as it approaches the center-stack,Lithium vapor spreading along the center-stack,In-board gas injector,Lithium Pellet moving through plasma after entering at 296ms,H. Kugel,Supersonic gas jet penetrates well through a thick scrape-off layer,DEGAS 2 Neutral transport modeling reproduces observed features,114449,camera,CHERS,Preliminary fueling efficiency estimate shows 3 - 4 times improvement over gas puff,LLNL,Quartz microbalance shows time resolved deposition on NSTX in geometry typical of a diagnostic mirror - results show significant deposition after plasma discharge.Novel electrostatic surface particle detector works well in air and vacuum environments.First time-resolved measurements of surface dust in tokamaks.,NSTX is developing ITER/BP relevant time resolved surface deposition monitors,C. Skinner,Solenoid-Free Start-UpTokamaks and STs must eliminate OH solenoidCoaxial Helicity InjectionOuter poloidal field start-up,Capacitor Bank for Transient-CHI Start-Up,Absorber,Injector, Successfully installed and commissioned new 2 kV, 100 kJ capacitor bank. Conducted initial experiments:Reduced the required gas pressure for a successful plasma break down by a factor of 3. Toroidal plasma currents of up to